It is a simple matter to change your In Game Name IGN!
Log in to your account and in the bottom left you will find your Profile Page, go there. Just to the right of your IGN will be a small pencil icon, tapping this will initiate the IGN edit feature.
Changing your IGN will cost 1300 ICE so make sure you have that much in your account before trying.
IGNs are cAsE seNsitiVe and do not allow special characters or spaces.